Physically separating distinct cooling zones in a machine cooling system may resolve hot air recirculation to the active fan heat exchangers. This can lead to higher system efficiencies but it may also reduce the cleaning of the cooling package and the efficacy of reversing fans. Any flow divider to separate zones will take up space and will need to seal tightly enough to prevent recirculation airflow. This sealing and complex geometry of dividers and zones may trap dirt and debris. By using passive fans at lower speeds to avoid recirculation, the overall cooling package can become easier to clean with a small tradeoff in cooling system efficiency.
It would be desirable to have a cooling system with an open cooling compartment where the cooling fans on different planes can pull ambient air from the same cooling compartment for cooling various machine systems without causing preheated air to be pulled back through other fans of the cooling system.